As medical science enters the 21st century, an enormous amount of new data is emerging from technological advances in data acquisition, computational power and algorithm development. However, there exist huge cognitive and cultural obstacles to translating this data into new knowledge, and to patient care. Mathematical modeling is emerging as a desirable approach by which to describe and predict the behavior of complex biological phenomena. A key barrier to the widespread implementation of complex modeling in acute illness is the gulf separating clinicians and bench researchers on the one hand, and modelers on the other. Further skepticism as to the utility of this integrated approach exists in large segments of academia entrenched in a epistemological paradigm of reductionist that, although time tested, may well prove insufficient to conquer the complex reality. To improve collaboration and dialog among these groups, we propose a yearly meeting entitled "International Conference on Complexity in Acute Illness". The goals of this conference are to 1) facilitate open exchange among clinicians, biological scientists, and modelers, 2) present original research in complex modeling of biological events relevant to acute illness, 3) provide a forum for young and underrepresented investigators to present and learn from interdisciplinary research, 4) launch an effort to standardize modeling efforts in human disease, and 5) promote scientific diffusion of these efforts by the publication of highlight presentations in a suitable scientific journal. We request support for the 2005 International Conference in Complexity in Acute Illness (ICCAI 2005), now the annual meeting of the newly incorporated Society for Complexity in Acute Illness, to be held September 29-October 1, 2005 in Cologne, Germany. We are building on the experience of three prior annual conferences (www.iccai.org). Themes to be covered in 2005 include 1) molecular modeling of acute inflammation, 2) organ function and dysfunction, 3) biological variability, and 4) obstacles to evidence-based modeling. We will also hold a postgraduate course on mathematical methods prior to the conference. Each thematic session, under the direction of a chair and co-chair, includes formal presentations by an international group of established scientists, followed by questions and discussion. We put a strong emphasis on seminar-type presentations by young researchers. Scientific abstracts will be solicited and meritorious ones selected for oral or poster presentations, and published in the December 1, 2005 issue of the peer reviewed Journal of Critical Care. [unreadable] [unreadable]